diff --git a/core/src/main/java/io/wcm/testing/mock/aem/MockExternalizer.java b/core/src/main/java/io/wcm/testing/mock/aem/MockExternalizer.java
index 837b4d72..ed7c845a 100644
--- a/core/src/main/java/io/wcm/testing/mock/aem/MockExternalizer.java
+++ b/core/src/main/java/io/wcm/testing/mock/aem/MockExternalizer.java
@@ -125,7 +125,7 @@ public String relativeLink(SlingHttpServletRequest request, String path) {
     return getMappedPath(request.getResourceResolver(), path);
   }
 
-  private String buildExternalLink(@Nullable ResourceResolver resourceResolver, String domain, String scheme, String path) {
+  private String buildExternalLink(@Nullable ResourceResolver resourceResolver, @NotNull String domain, @Nullable String scheme, @NotNull String path) {
     URI domainURI = domainMappings.get(Objects.requireNonNull(domain));
     if (domainURI == null) {
       throw new IllegalArgumentException("No mapping defined for: " + domain);
@@ -149,7 +149,7 @@ private String buildExternalLink(@Nullable ResourceResolver resourceResolver, St
     return url.toString();
   }
 
-  private String buildAbsoluteLink(@NotNull SlingHttpServletRequest request, String scheme, String path) {
+  private String buildAbsoluteLink(@NotNull SlingHttpServletRequest request, @NotNull String scheme, @NotNull String path) {
 
     // return path unchanged if it is already absolute (or if no request available)
     if (StringUtils.contains(path, SCHEME_SEPARATOR)) {
diff --git a/core/src/test/java/io/wcm/testing/mock/aem/MockExternalizerSlingMappingTest.java b/core/src/test/java/io/wcm/testing/mock/aem/MockExternalizerSlingMappingTest.java
index 993881b7..0b9da2a4 100644
--- a/core/src/test/java/io/wcm/testing/mock/aem/MockExternalizerSlingMappingTest.java
+++ b/core/src/test/java/io/wcm/testing/mock/aem/MockExternalizerSlingMappingTest.java
@@ -2,7 +2,7 @@
  * #%L
  * wcm.io
  * %%
- * Copyright (C) 2021 wcm.io
+ * Copyright (C) 2024 wcm.io
  * %%
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.